Research progress of mass-spectrometric technique in nucleic acid detection and analysis / 中华预防医学杂志

Mass spectrometry is a spectroscopic technique for detecting the molecular weight of substances based on mass spectrometry equipment. Many types of mass spectrometry with different functions are widely used in scientific research and application technology development in various disciplines. In recent years, mass spectrometry has shown great potential in nucleic acid detection. In particular, matrix-assisted laser desorption/ionization time of flight mass spectrometry has become a research hotspot due to its velocity, high throughput, and accuracy. The nucleic acid research by mass spectrometry is highlighted in single nucleotide polymorphism, gene mutation, DNA methylation analysis, and DNA copy number variations. This article reviews the research and application of mass spectrometry in nucleic acid detection and analysis to provide a reference for the development of new detection technology for nucleic acid based on mass spectrometry.

Research progress of mass-spectrometric technique in nucleic acid detection and analysis / 中华预防医学杂志

Mass spectrometry is a spectroscopic technique for detecting the molecular weight of substances based on mass spectrometry equipment. Many types of mass spectrometry with different functions are widely used in scientific research and application technology development in various disciplines. In recent years, mass spectrometry has shown great potential in nucleic acid detection. In particular, matrix-assisted laser desorption/ionization time of flight mass spectrometry has become a research hotspot due to its velocity, high throughput, and accuracy. The nucleic acid research by mass spectrometry is highlighted in single nucleotide polymorphism, gene mutation, DNA methylation analysis, and DNA copy number variations. This article reviews the research and application of mass spectrometry in nucleic acid detection and analysis to provide a reference for the development of new detection technology for nucleic acid based on mass spectrometry.

The Significance of the Nucleic Acid Test (NAT) to Prevent Viral Contamination in Musculoskeletal Tissue Transplantation / A importância da realização do teste de ácidos nucleicos (NAT) para a prevenção de contaminação viral nos transplantes de tecidos musculoesqueléticos

Abstract Objective The present study aims to highlight the significance of the nucleic acid test (NAT) for musculoskeletal tissue donation and to compare the sensitivity of this test on the different available platforms. Method The present study is a retrospective survey in a human tissue bank database and an integrative literature review encompassing the last 10 years. The PubMed portal and the SCOPUS, CINAHL, and Web of Science databases were queried for articles. Results We found no specific studies on the use and sensitivity of NAT in braindead tissue donors. The information presented in the present study consists of specific contents intended for the Brazilian Blood Transfusion Network (Hemorrede Transfusional Nacional, in Portuguese) and internal retrospective data from a tissue bank located at a city in the state of São Paulo, Brazil. Conclusions The NAT is effective in blood samples from living patients. However, since biochemical reactions in braindead patients can be different, specific research, platforms, or both are crucial to tissue banks.

Resumo Objetivo Evidenciar a importância da realização do teste de ácido nucleico (NAT, na sigla em inglês) para doação de tecidos musculoesqueléticos, assim como comparar a sensibilidade deste exame nas diferentes plataformas existentes no mercado. Método Trata-se de um levantamento retrospectivo no banco de dados de um determinado Banco de Tecidos Humanos e de uma revisão integrativa da literatura, operacionalizada nos últimos 10 anos. As buscas de artigos ocorreram no portal PubMed e nas bases de dados SCOPUS, CINAHL e Web of Science. Resultados Não foram encontrados estudos específicos sobre a utilização e a sensibilidade do exame NAT em pacientes doadores de tecidos com morte encefálica (ME), sendo as informações apresentadas no presente estudo conteúdos específicos destinados à Hemorrede Transfusional Nacional e aos dados retrospectivos internos de um Banco de Tecidos do interior do estado de São Paulo, Brasil. Conclusões O exame NAT se apresenta efetivo em amostras de sangue de pacientes vivos. Porém, reações bioquímicas em pacientes com condições de ME podem se apresentar de formas diferenciadas, tornando-se indispensáveis a realização de pesquisas específicas e/ou a indicação de plataformas aos Bancos de Tecidos.

Study of incubation period of infection with 2019-nCoV Omicron variant BA.5.1.3 / 中华流行病学杂志

Objective: To study the incubation period of the infection with 2019-nCoV Omicron variant BA.5.1.3. Methods: Based on the epidemiological survey data of 315 COVID-19 cases and the characteristics of interval censored data structure, log-normal distribution and Gamma distribution were used to estimate the incubation. Bayes estimation was performed for the parameters of each distribution function using discrete time Markov chain Monte Carlo algorithm. Results: The mean age of the 315 COVID-19 cases was (42.01±16.54) years, and men accounted for 30.16%. A total of 156 cases with mean age of (41.65±16.32) years reported the times when symptoms occurred. The log-normal distribution and Gamma distribution indicated that the M (Q1, Q3) of the incubation period from exposure to symptom onset was 2.53 (1.86, 3.44) days and 2.64 (1.91, 3.52) days, respectively, and the M (Q1, Q3) of the incubation period from exposure to the first positive nucleic acid detection was 2.45 (1.76, 3.40) days and 2.57 (1.81, 3.52) days, respectively. Conclusions: The incubation period by Bayes estimation based on log-normal distribution and Gamma distribution, respectively, was similar to each other, and the best distribution of incubation period was Gamma distribution, the difference between the incubation period from exposure to the first positive nucleic acid detection and the incubation period from exposure to symptom onset was small. The median of incubation period of infection caused by Omicron variant BA.5.1.3 was shorter than those of previous Omicron variants.

Related factors of negative conversion time of nucleic acid in children with COVID-19 / 中华儿科杂志

Objective: To explore the related factors of negative conversion time (NCT) of nucleic acid in children with COVID-19. Methods: A retrospective cohort study was conducted. A total of 225 children who were diagnosed with COVID-19 and admitted to Changxing Branch of Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from April 3rd to May 31st 2022 were enrolled in the study. The infection age, gender, viral load, basic disease, clinical symptoms and information of accompanying caregivers were retrospectively analyzed. According to age, the children were divided into<3 years of age group and 3-<18 years of age group. According to the viral nucleic acid test results, the children were divided into positive accompanying caregiver group and negative accompanying caregiver group. Comparisons between groups were performed using Mann-Whitney U test or Chi-square test. Multivariate Logistic regression analysis was used to analyze the related factors of NCT of nucleic acid in children with COVID-19. Results: Among the 225 patients (120 boys and 105 girls) of age 2.8 (1.3, 6.2) years, 119 children <3 years and 106 children 3-<18 years of age, 19 cases were diagnosed with moderate COVID-19, and the other 206 cases were diagnosed with mild COVID-19. There were 141 patients in the positive accompanying caregiver group and 84 patients in the negative accompanying caregiver group.Patients 3-<18 years of age had a shorter NCT (5 (3, 7) vs.7 (4, 9) d, Z=-4.17, P<0.001) compared with patients <3 years of age. Patients in the negative accompanying caregiver group had a shorter NCT (5 (3, 7) vs.6 (4, 9) d,Z=-2.89,P=0.004) compared with patients in the positive accompanying caregiver group. Multivariate Logistic regression analysis showed that anorexia was associated with NCT of nucleic acid (OR=3.74,95%CI 1.69-8.31, P=0.001). Conclusion: Accompanying caregiver with positive nucleic acid test may prolong NCT of nucleic acid, and decreased appetite may be associated with prolonged NCT of nucleic acid in children with COVID-19.

CRISPR-based molecular diagnostics: a review / 生物工程学报

Rapid and accurate detection technologies are crucial for disease prevention and control. In particular, the COVID-19 pandemic has posed a great threat to our society, highlighting the importance of rapid and highly sensitive detection techniques. In recent years, CRISPR/Cas-based gene editing technique has brought revolutionary advances in biotechnology. Due to its fast, accurate, sensitive, and cost-effective characteristics, the CRISPR-based nucleic acid detection technology is revolutionizing molecular diagnosis. CRISPR-based diagnostics has been applied in many fields, such as detection of infectious diseases, genetic diseases, cancer mutation, and food safety. This review summarized the advances in CRISPR-based nucleic acid detection systems and its applications. Perspectives on intelligent diagnostics with CRISPR-based nucleic acid detection and artificial intelligence were also provided.

Clinical features of severe acute respiratory syndrome coronavirus 2 Omicron variant infection in children: an analysis of 201 cases / 中国当代儿科杂志

OBJECTIVES@#To study the clinical features of children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection.@*METHODS@#A retrospective analysis was performed on the medical data of 201 children with coronavirus disease 2019 (COVID-19) who were hospitalized and diagnosed with SARS-CoV-2 Omicron variant infection in Quanzhou First Hospital from March 14 to April 7, 2022. Among the 201 children, there were 34 children with asymptomatic infection and 167 with symptomatic infection. The two groups were compared in terms of clinical features, results of experimental examinations, and outcome.@*RESULTS@#Of all the 201 children, 161 (80.1%) had a history of exposure to COVID-19 patients and 132 (65.7%) had a history of COVID-19 vaccination. Among the 167 children with symptomatic infections, 151 had mild COVID-19 and 16 had common COVID-19, with no severe infection or death. Among the 101 children who underwent chest CT examination, 16 had ground glass changes and 20 had nodular or linear opacities. The mean time to nucleic acid clearance was (14±4) days for the 201 children with Omicron variant infection, and the symptomatic infection group had a significantly longer time than the asymptomatic infection group [(15±4) days vs (11±4) days, P<0.05]. The group vaccinated with one or two doses of COVID-19 vaccine had a significantly higher positive rate of IgG than the group without vaccination (P<0.05). The proportions of children with increased blood lymphocyte count in the symptomatic infection group was significantly lower than that in the asymptomatic infection group (P<0.05). Compared with the asymptomatic infection group, the symptomatic infection group had significantly higher proportions of children with increased interleukin-6, increased fibrinogen, and increased D-dimer (P<0.05).@*CONCLUSIONS@#Most of the children with Omicron variant infection have clinical symptoms, which are generally mild. The children with symptomatic infection are often accompanied by decreased or normal blood lymphocyte count and increased levels of interleukin-6, fibrinogen, and D-dimer, with a relatively long time to nucleic acid clearance. Some of them had ground glass changes on chest CT.

Plasmid DNA extraction by double magnetic beads method and its application / 生物工程学报

Plasmids are the most commonly used gene carriers in the field of gene synthesis and sequencing. However, the main problems faced by traditional plasmid DNA extraction technology are low extraction throughput and high production cost, so they cannot meet the growing demand. In this study, a double-magnetic-bead method (DMBM) for plasmid extraction was developed based on the principle of plasmid extraction. The effects of the input of magnetic beads, the size of plasmid DNA fragments, and the volume of bacterial on plasmid DNA extraction were explored. In addition, the quality, throughput, and cost of plasmid DNA extraction were also compared between this technique and the commercial plasmid DNA extraction kits. The results showed that the DMBM can meet the needs of extracting plasmid DNA with different cell densities and fragment lengths. Moreover, the sensitivity and quality of plasmid extraction by the DMBM method were both superior to those of the centrifugal adsorption column method. In addition, this technique could be applied on a 96-channel automated nucleic acid extractor, resulting in higher purity of the extracted plasmid DNA, 80% reduction in extraction time, and 57.1% reduction in cost. It also reduces manual operations, achieving high-throughput and low-cost plasmid DNA extraction, thus may facilitate gene synthesis and sequencing.

Cost-effectiveness analysis of Chaiyin Granules in treatment of influenza / 中国中药杂志

This study aimed to evaluate the cost-effectiveness of Chaiyin Granules compared with Oseltamivir Phosphate Capsules in the treatment of influenza(exogenous wind-heat syndrome). Based on a randomized, double-blind, positive drug parallel control clinical trial, this study evaluated the pharmacoeconomics of Chaiyin Granules with cost-effectiveness analysis method. A total of 116 patients with influenza from eight hospitals(grade Ⅱ level A above) in 6 cities were selected in this study, including 78 cases in the experimental group with Chaiyin Granules and Oseltamivir Phosphate Capsules placebo, and 38 cases in the control group with Oseltamivir Phosphate Capsules and Chaiyin Granules placebo. The total cost of this study included direct medical cost, direct non-medical cost, and indirect cost. The remission time of clinical symptoms, cure time/cure rate, antipyretic onset time/complete antipyretic time, viral nucleic acid negative rate, and traditional Chinese medicine(TCM) syndrome curative effect were selected as the effect indicators for cost-effectiveness analysis. Four-quadrant diagram was used to estimate the incremental cost-effectiveness ratio. The results showed that Chaiyin Granules were not inferior to Oseltamivir Phosphate Capsules in the remission time of clinical symptoms of influenza(3.1 d vs 2.9 d, P=0.360, non-inferiority margin was 0.5 d). Compared with Oseltamivir Phosphate Capsules, Chaiyin Granules would delay the remission time of clinic symptoms of influenza for 1 d, but could save 213.9 yuan. 1 d delay in cure time could save 149.3 yuan; 1% reduction in the cure rate could save 8.2 yuan; 1 d delay in antipyretic onset time could save 295.4 yuan; 1 d delay in complete antipyretic time could save 114.3 yuan; 1% reduction in the 5-day cure rate of TCM syndrome could save 19.2 yuan. Different from other indicators, there was no statistically significant difference between two groups in the effect of negative conversion rate of viral nucleic acid, but the cost was lower and the effect was superior, and the pharmacoeconomics was not different from that of Oseltamivir Phosphate Capsules in the field of influenza treatment.

Research progress on plant-derived exosome-like nanoparticles and their applications / 中国中药杂志

Plant-derived exosome-like nanoparticles(PELNs) are a class of membranous vesicles with diameters approximately ranging from 30 to 300 nm, isolated from plant tissues. They contain components such as proteins, lipids, and nucleic acids. PELNs play an important role in the metabolism of plant substances and immune defense, and can also cross-regulate the physiological activities of fungi and animal cells, showing significant potential applications. In recent years, research on PELNs has significantly increased, highlighting three main issues:(1) the mixed sources of plant materials for PELNs;(2) the lack of a unified system for isolating and characterizing PELNs;(3) the urgent need to elucidate the molecular mechanisms underlying the cross-regulation of biological functions by PELNs. This article focused on these concerns. It began by summarizing the biological origin and composition of PELNs, discussing the techniques for isolating and characterizing PELNs, and analyzing their biomedical applications and potential future research directions., aiming to promote the establishment of standardized research protocols for PELNs and provide theoretical references for in-depth exploration of the mechanisms underlying PELNs' cross-regulatory effects.

Performance of screening of contacts of COVID-19 cases in same flight / 中华流行病学杂志

Objective: To understand the performance of 2019-nCoV nucleic acid detection in screening of contacts of COVID-19 cases in same flights and provide evidence for the effective screening of persons at high risk for the infection in domestic flights. Methods: The information of passengers who took same domestic flights with COVID-19 cases in China from April 1, 2020 to April 30, 2022 were retrospectively collected,and χ2 test was used to analyze positive nucleic acid detection rates in the passengers in different times before the onsets of the index cases, in different seat rows and in epidemic periods of different 2019-nCoV variants. Results: During the study period, a total of 433 index cases were identified among 23 548 passengers in 370 flights. Subsequently, 72 positive cases of 2019-nCoV nucleic acid were detected in the passengers, in whom 57 were accompanying persons of the index cases. Further analysis of the another 15 passengers who tested positive for the nucleic acid showed that 86.67% of them had onsets or positive detections within 3 days after the diagnosis of the index cases, and the boarding times were all within 4 days before the onsets of the index cases. The positive detection rate in the passengers who seated in first three rows before and after the index cases was 0.15% (95%CI: 0.08%-0.27%), significantly higher than in the passengers in other rows (0.04%, 95%CI: 0.02%-0.10%, P=0.007),and there was no significant difference in the positive detection rate among the passengers in each of the 3 rows before and after the index cases (P=0.577). No significant differences were found in the positive detection rate in the passengers, except the accompanying persons, among the epidemics caused by different 2019-nCoV variants (P=0.565). During the Omicron epidemic period, all the positive detections in the passengers, except the accompanying persons, were within 3 days before the onset of the index cases. Conclusions: The screening test of 2019-nCoV nucleic acid can be conducted in the passengers took the same flights within 4 days before the onsets of the index cases on board. Passengers who seated within 3 rows from the index cases can considered as the close contacts at high risk for 2019-nCoV, for whom screening should be conducted first and special managements are needed. The passengers in other rows can be classified as general risk persons for screening and management.

Establishment of a recombined mannose-binding lectin protein-magnetic beads-enriched binding recombinant enzyme-assisted polymerase chain reaction assay for Candida in blood samples / 中华流行病学杂志

Objective: To establish a nested recombinant enzyme-assisted polymerase chain reaction (RAP) technique combined with recombined mannose-binding lectin protein (M1 protein)-magnetic beads enrichment for the detection of Candida albicans (C. albicans) and Candida tropicalis (C. tropicalis) in blood samples for the early diagnosis of candidemia albicans and candidiemia tropicalis. Methods: The primer probes for highly conserved regions of the internal transcribed spacerregions of C. albicans and C. tropicalis were deigned to establish RAP assays for the detections of C. albicans and C. tropicalis; The sensitivity and reproducibility of nucleic acid tests with gradient dilutions of standard strains and specificity of nucleic acid tests with common clinical pathogens causing bloodstream infection were condcuted. M1 protein-magnetic bead enriched plasma C. albicans and C. tropicalis were used for RAP and PCR in with simulated samples and the results were compared. Results: The sensitivity of the established dual RAP assay was 2.4-2.8 copies/reaction, with higher reproducibility and specificity. M1 protein-magnetic bead enrichment of pathogen combined with the dual RAP assay could complete the detections of C. albicans and C. tropicalis in plasma within 4 hours. Fie the pathogen samples at concentration <10 CFU/ml, the number of the samples tested by RAP was higher than that tested by PCR after enrichment. Conclusion: In this study, a dual RAP assay for the detections of C. albicans and C. tropicalis in blood sample was developed, which has the advantages of accuracy, rapidity, and less contaminants and has great potential for rapid detection of Candidemia.

Clinical characteristics of children with Omicron variant infection in Chengdu area, China / 中国当代儿科杂志

OBJECTIVES@#To investigate the clinical characteristics of children infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Chengdu of China.@*METHODS@#A retrospective analysis was conducted for the clinical data of 226 children who were infected with the Omicron variant of SARS-Cov-2 and were isolated and treated in Chengdu Shelter Hospital from August 28 to September 21, 2022. According to the presence or absence of clinical symptoms, they were divided into two groups: asymptomatic group and mild symptomatic group. The two groups were compared in terms of clinical characteristics, diagnosis and treatment, and prognosis.@*RESULTS@#Among the 226 children infected with the Omicron variant, 71 (31.4%) were asymptomatic and 155 (68.6%) had mild symptoms. Fever and cough were the most common clinical symptoms, with fever in 95 children (61.3%) and cough in 92 children (59.4%). Of all 226 children, 188 (83.2%) received coronavirus disease 2019 (COVID-19) vaccination. The time to nucleic acid clearance ranged from 6 to 26 days, with a nucleic acid clearance rate of 58.0% (131/226). There were no significant differences among different age groups in sex, early symptoms, clinical typing, nucleic acid re-positive rate, nucleic acid clearance rate, and length of hospital stay (P>0.05). There were no significant differences between the asymptomatic and mild symptomatic groups in age, sex, underlying diseases, COVID-19 vaccination, use of Lianhua Qingwen granules, nucleic acid clearance rate, nucleic acid re-positive rate, and length of hospital stay (P>0.05).@*CONCLUSIONS@#Children infected with the Omicron variant of SARS-Cov-2 in Chengdu generally have mild clinical symptoms, mainly upper respiratory tract infection, which has little threat to the health of children of different ages, and children tend to have a good overall prognosis.

Advances in modification and delivery of nucleic acid drugs / 浙江大学学报·医学版

Nucleic acid-based drugs, such as RNA and DNA drugs, exert their effects at the genetic level. Currently, widely utilized nucleic acid-based drugs include nucleic acid aptamers, antisense oligonucleotides, mRNA, miRNA, siRNA and saRNA. However, these drugs frequently encounter challenges during clinical application, such as poor stability, weak targeting specificity, and difficulties in traversing physiological barriers. By employing chemical modifications of nucleic acid structures, it is possible to enhance the stability and targeting specificity of certain nucleic acid drugs within the body, thereby improving delivery efficiency and reducing immunogenicity. Moreover, utilizing nucleic acid drug carriers can facilitate the transportation of drugs to lesion sites, thereby aiding efficient intracellular escape and promoting drug efficacy within the body. Currently, commonly employed delivery carriers include virus vectors, lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, protein carriers and extracellular vesicles. Nevertheless, individual modifications or delivery carriers alone are insufficient to overcome numerous obstacles. The integration of nucleic acid chemical modifications with drug delivery systems holds promise for achieving enhanced therapeutic effects. However, this approach also presents increased technical complexity and clinical translation costs. Therefore, the development of nucleic acid drug carriers and nucleic acid chemical modifications that are both practical and simple, while maintaining high efficacy, low toxicity, and precise nucleic acid delivery, has become a prominent research focus in the field of nucleic acid drug development. This review comprehensively summarizes the advancements in nucleic acid-based drug modifica-tions and delivery systems. Additionally, strategies to enhance nucleic acid drug delivery efficiency are discussed, with the aim of providing valuable insights for the translational application of nucleic acid drugs.

Research progress in mitochondrial gene editing technology / 浙江大学学报·医学版

Mitochondrial DNA (mtDNA) mutations result in a variety of genetic diseases. As an emerging therapeutic method, mtDNA editing technology recognizes targets more based on the protein and less on the nucleic acid. Although the protein recognition type mtDNA editing technology represented by zinc finger nuclease technology, transcription activator like effector nuclease technology and base editing technology has made some progress, the disadvantages of complex recognition sequence design hinder further popularization. Gene editing based on nucleic acid recognition by the CRISPR system shows superiority due to the simple structure, easy design and modification. However, the lack of effective means to deliver nucleic acids into mitochondria limits application in the field of mtDNA editing. With the advances in the study of endogenous and exogenous import pathways and the deepening understanding of DNA repair mechanisms, growing evidence shows the feasibility of nucleic acid delivery and the broad application prospects of nucleic acid recognition type mtDNA editing technology. Based on the classification of recognition elements, this article summarizes the current principles and development of mitochondrial gene editing technology, and discusses its application prospects.

Tracking analysis of viral nucleic acid Ct value in patients with re-positive SARS-CoV-2 infection / 中华危重病急救医学

OBJECTIVE@#To track analysis of viral nucleic acid test results in patients with re-positive SARS-CoV-2 infection, and provide clinical reference for nucleic acid test of re-positive cases.@*METHODS@#A retrospective study was conducted. The multiple nucleic acid results of 96 cases with SARS-CoV-2 infection tested by medical laboratory of Shenzhen Luohu Hospital Group from January to September in 2022 were analyzed. The test dates and cycle threshold (Ct) values of detectable positive virus nucleic acid in the 96 cases were summarized and analyzed.@*RESULTS@#A total of 96 patients with SARS-CoV-2 infection were retested re-sampled for nucleic acid testing at least 12 days after the initial positive screening. Among them, 54 cases (56.25%) had Ct value of < 35 for nucleocapsid protein gene (N) and/or open reading frame 1ab gene (ORF 1ab), 42 cases (43.75%) had Ct value ≥ 35. In the re-sampling of infected patients, N gene titers were 25.08 to 39.98 Ct cycles, and ORF 1ab gene titers were 23.16 to 39.56 Ct cycles. Compared with the positive results of the initial screening, the Ct values of N gene and/or ORF 1ab gene positive were increased in 90 cases (93.75%). Among them, the patients with the longest duration of nucleic acid positive could still be positive for double targets (the Ct value of N gene was 38.60, and the Ct value of ORF 1ab gene was 38.11) at an interval of 178 days after the initial positive screening.@*CONCLUSIONS@#Patients infected with SARS-CoV-2 can be sustained or repeatedly tested positive for nucleic acid for a long period of time, and most of them had Ct values < 35. But whether it is infectious needs to be comprehensively evaluated by combining epidemiology, variant type, samples with the alive virus, and clinical symptoms and signs.

Laboratory testing strategies for human immunodeficiency virus (HIV) in blood donors / 细胞与分子免疫学杂志

Objective To propose the blood detection strategies for human immunodeficiency virus (HIV) among blood donors, and provide reference for the detection, early diagnosis and transmission blocking of HIV. Methods A total of 117 987 blood samples from blood donors were screened using the third- and fourth-generation ELISA HIV detection reagents. Western blot analysis was used to verify the reactive results of the third-generation reagent alone, or both the third-generation and fourth-generation reagents. HIV nucleic acid test was carried out for those with negative test results of the third- and fourth-generation reagents. For those with positive results of the fourth-generation reagent only, nucleic acid test followed by a confirmatory test by Western blot analysis was carried out. Results 117 987 blood samples from blood donors were tested by different reagents. Among them, 55 were tested positive by both the third- and fourth-generation HIV detection reagents at the same time, accounting for 0.047% and 54 cases were confirmed HIV-positive by Western blot analysis, and 1 case was indeterminate, then turned positive during follow-up testing. 26 cases were positive by the third-generation reagent test alone, among which 24 cases were negative and 2 were indeterminate by Western blot analysis. The band types were p24 and gp160 respectively detected by Western blot analysis, and were confirmed to be HIV negative in follow-up testing. 31 cases were positive by the fourth-generation HIV reagent alone, among which 29 were negative by nucleic acid test, and 2 were positive according to the nucleic acid test.Western blot analysis was used to verify that the two cases were negative. However, after 2~4 weeks, the results turned positive when the blood sample was retested by Western blot analysis during the follow-up of these two cases. All the specimens that were tested negative by both the third- and fourth-generation HIV reagents were validated negative by HIV nucleic acid test. Conclusion A combined strategy with both third- and fourth-generation HIV detection reagents can play a complementary role in blood screening among blood donors. The application of complementary tests, such as nucleic acid test and Western blot analysis, can further improve the safety of blood supply, thus contributing to the early diagnosis, prevention, transmission and treatment of blood donors potentially infected by HIV.

A cross-sectional study of enterovirus nucleic acid test with throat swabs for term late neonates during coronavirus disease 2019 / 中国当代儿科杂志

OBJECTIVES@#To investigate the positive rate of enterovirus (EV) nucleic acid in throat swabs of term late neonates hospitalized during the coronavirus disease 2019 (COVID-19) epidemic and the clinical characteristics of the neonates.@*METHODS@#A single-center cross-sectional study was performed on 611 term late infants who were hospitalized in the neonatal center from October 2020 to September 2021. Throat swabs were collected on admission for coxsackie A16 virus/EV71/EV universal nucleic acid testing. According to the results of EV nucleic acid test, the infants were divided into a positive EV nucleic acid group (8 infants) and a negative EV nucleic acid group (603 infants). Clinical features were compared between the two groups.@*RESULTS@#Among the 611 neonates, 8 tested positive for EV nucleic acid, with a positive rate of 13.1‰, among whom 7 were admitted from May to October. There was a significant difference in the proportion of infants contacting family members with respiratory infection symptoms before disease onset between the positive and negative EV nucleic acid groups (75.0% vs 10.9%, P<0.001). There were no significant differences between the two groups in demographic data, clinical symptoms, and laboratory test results (P>0.05).@*CONCLUSIONS@#There is a certain proportion of term late infants testing positive for EV nucleic acid in throat swabs during the COVID-19 epidemic, but the proportion is low. The clinical manifestations and laboratory test results of these infants are non-specific. Transmission among family members might be an important cause of neonatal EV infection.

Pathological study on the relationship between nucleic acid oxidative stress and heart failure with preserved ejection fraction in patients aged over 85 years / 中华心血管病杂志

Objective: To investigate the level of nucleic acid oxidation in myocardial tissue of patients aged over 85 with heart failure with preserved ejection fraction (HFpEF) and the correlation with myocardial amyloid deposition. Methods: This was a retrospective case-control study. Data of patients≥85 years old who underwent systematic pathological autopsy in Beijing Hospital from 2003 to 2017 were retrospectively collected. Twenty-six patients were included in the HFpEF group and 13 age-and sex-matched patients who had not been diagnosed with heart failure and died of non-cardiovascular diseases served as the control group. The left ventricular myocardium slices of both groups were semi-quantitatively analyzed using immunohistochemical staining of 8-oxidized guanine riboside (8-oxo-G) and 8-oxidized guanine deoxyriboside (8-oxo-dG) to evaluate the oxidation of RNA and DNA in cardiomyocytes. Using the median of the mean absorbance value of 8-oxo-G immunohistochemical staining as the cut-off value, patients were divided into high-absorbance group and low-absorbance group. Congo red staining was used to compare myocardial amyloid deposition between the two groups. Results: The mean age of patients in HFpEF group was (91.8±3.7) years, 24 (92.3%) were males. The mean age of patients in control group was (91.7±3.7) years old, 11 (84.6%) were males. The median mean optical absorbance value of 8-oxo-G immunohistochemical staining of myocardium was significantly higher in HFpEF patients than in control group (0.313 8 (0.302 2, 0.340 6) vs. 0.289 2 (0.276 7, 0.299 4), Z=-3.245, P=0.001). The median mean absorbance value of 8-oxo-dG immunohistochemical staining of myocardial tissue was similar between the two groups (0.300 0 (0.290 0, 0.322 5) vs. 0.300 0 (0.290 0, 0.320 0), Z=-0.454, P=0.661). Proportion of patients with moderate and severe cardiac amyloid deposition was significantly higher in the high-absorbance group than in the low-absorbance group ((85.0%, 17/20) vs. (31.6%, 6/19), P=0.001). Conclusion: The RNA oxidation degree of myocardium in HFpEF patients is higher than that in elderly people without heart failure. Degree of myocardial amyloid deposits is higher in patients with high levels of RNA oxidation.

Analysis of the reentry status of blood donors with reactive bloodborne pathogen screening markers in Hangzhou City / 中华预防医学杂志

Objective: To explore the reentry rate of reactive blood donors in the bloodborne pathogen infection screening in Hangzhou City, and analyze the donation behavior of those who successfully returned. Methods: A retrospective analysis of the return data of blood donors with reactive bloodborne pathogen screening markers was conducted at Zhejiang Provincial Blood Center from June 2017 to May 2022. The reentry process for blood donors with reactive bloodborne pathogen screening markers in Hangzhou City is as follows: after the initial screening period of 6 months, donors can voluntarily apply for return to the blood center. Samples are collected and subjected to routine enzyme-linked immunosorbent assay (ELISA) screening for HBsAg, anti-HCV, HIV Ab/Ag, and anti-TP, as well as a single nucleic acid (HIV/HCV/HBV) test. For samples that show non-reactivity in both ELISA and nucleic acid tests, serum biomarker testing for the reasons of exclusion is performed using chemiluminescence immunoassay (CLIA), and those with non-reactivity are allowed to return. Results: A total of 4 583 reactive blood donors who met the criteria for re-entry applied for reentry, out of which 475 applications were received from donors in the Hangzhou area. Among these, 279 donors were successfully readmitted, resulting in a success rate of 58.74% (279/475). By the end of December 2021, out of the 174 donors who successfully returned, 114 donors chose to donate again. They collectively donated 39 530 ml of whole blood and 1 147.2 therapeutic doses of platelets. Among these, 21 donors once again showed reactivity for pathogen infection biomarkers, accounting for 18.42% (21/114). Conclusion: The reentry strategy has somewhat mitigated the attrition of blood donors. Nevertheless, there are instances where donors who were successfully readmitted show reactivity once more in the screening for pathogen infection biomarkers.